One Year Experimental Evaluation of the Electrical Gain by Solar Tracking a 12 KW Photovoltaic System Installed on a Building Rooftop

Abstract

To fulfil the requirements of the European Directive 31/2010, by January 2021, all new buildings and those undergoing major renovation must have renewable energy systems implemented on or near the building targeting the nearly Zero Energy Building standard. In areas with high density of buildings the available surfaces to install solar energy conversion systems are limited. A solution to tackle this issue consists of implementing solar tracking systems to increase the amount of received solar energy and thus, the thermal or electrical energy output of the solar energy conversion system. A solar tracking mechanism, with 2 DOF and mono-axial diurnal movement implemented in the Renewable Energy Systems and Recycling R&D Centre of the Transilvania University of Brasov, Romania is presented in the paper. This mechanism simultaneously rotates eight photovoltaic strings (each string consisting of six photovoltaic modules) around North-South oriented horizontal axes. Experimental results obtained during 2018 are comparatively presented in the paper for the solar tracking photovoltaic system kept in a fixed position for the first six months of 2018 and with active solar tracking system during the last six months of 2018. Significant solar tracking gain of 59.4% resulted for the sunniest clear sky days in the monitoring period. When considering the entire monitoring period of six months with active solar tracking system vs. the six months in fixed position, a solar tracking gain of 24.89% resulted.